The use of adhesives in electronic industry is well known and in the prior art there are described various adhesive compositions used for this purpose. An example of such an adhesive composition can be found in a handbook "Non metallic materials . . . " by Tcherniak K. I., Sudostroenie, 1966, pp. 229-231. This composition is based on polychloroprene rubber, titan dioxide and triphenylmethane triisocyanate. The main disadvantage of this composition lies in the fact that it reacts with copper of the conducting wiring and this deteriorates the reliability of bonding.
There is known another adhesive composition, as described for example in "Handbook of elastomeric coatings and sealants in shipbuilding" by Mudrov O. A., Savchenko I. M. and Shitov V. S., Leningrad, Sudostroenie, 1982, pp. 135-137. This adhesive composition designated as EKM includes polydieneurethane diepoxide epoxy resin, amine curing agent and a filler. Unfortunately this composition is not convenient in use since it hardens only after heating at elevated temperatures and therefore it undergoes corrosion in contact with copper.
There are known also another adhesive composition as described in Akiguchi's U.S. Pat. No. 5,427,642, which suffers from the same disadvantage seeing that it also should be heated in order to cause the hardening thereof.
The most relevant to the subject of the present invention is an adhesive composition, which is disclosed in a book "Synthetic glues" by Kardashov D. A., Chimia, 1976, p.285. This composition includes a cross-linkable synthetic rubber, a filler, triphenyl-methane, 4,4'4" triisocyanate and a solvent. As a synthetic rubber, butadiene-styrene rubber is used. This adhesive composition hardens at room temperature, it does not react with copper and it is resistant to humidity. Unfortunately its adhesive strength deteriorates in condition of thermal shock and therefore performances of this composition are not sufficiently reliable for the use in electronic industry.
Thus despite of existence of various adhesive composition available for fastening of various components in electronic industry there still exists a need in a new and improved composition having high adhesive strength, which does not react with copper and which can be easily integrated in the existing manufacturing process.